Generally, a hoist is used when hoisting a certain weight thing. The hoist is provided with a hook at an end of a wining rope for hoisting a weight thing with the help of a driving unit, a gear deceleration device, a brake or something. The hoist is classified into a manual hoist driven with hands, and an electric hoist which uses a motor and is installed on a rail of a crane and moves along the same.
Since the hoist is used for hoisting a weight thing up and down, a certain tuning device is needed when turning the hoisted thing.
FIG. 1 is a perspective view illustrating a turning device for a hoist (utility model number 20-341231) which is connected with a hoist for turning a certain hoisted thing. The turning device 1 comprises a motor 2, a decelerator 3 connected with the motor 2, a brake 4 connected with the decelerator 3, a friction pulley 5 connected with the decelerator 3, and a belt (not shown) of which one end is wound on the friction pulley 5, and the other end is wound on a weight thing for thereby turning the weight thing as the friction pulley 5 is rotated.
In the above turning device, when the friction pulley 5 is rotated, the belt contacting with the same is driven, and the connected weight thing is turned. The conventional turning device 1 is characterized in that a friction force between the friction pulley 5 and the belt decreases when it is used for a long time, so that a certain slippery may occur between the friction pulley 5 and the belt when turning the hoisted weight thing. So, a desired reliable turning work is not obtained. Since the motor 2 is unnecessarily operated, the motor 2 may be aged, and a power consumption increases.
The turning device for a conventional hoist is used in a state that a fixture 6 of the turning device 1 is hung on the hook of the hoist. So, when a large weight thing is hung on the turning device 1, an over weight is applied to the hoist, so that the hoist may be damaged, and a safety accident may occur.
As another problem of the conventional turning device, the turning device 1 is installed at the hook of the hoist during the turning work. When it is needed to use the hoist after the turning work is finished, the turning device 1 should be separated, so that the work process is complicated, and the work time is delayed.
FIG. 2, FIGS. 3 and 4 are views illustrating the turning device (utility model number 20-415071) for a hoist invented by the same applicant as the present application for overcoming the problems of FIG. 1. FIGS. 2 and 3 are a side view and a plane view illustrating a turning device for a hoist. FIG. 4 is a side view illustrating a state of use. The turning device 10 comprises a first hoist unit 11 and a second hoist unit 21, and a connection member 31 for connecting the first and second hoist units 11 and 21.
The first and second hoist units 11 and 21 are provided with the first and second hoist frames 12, and 22, respectively. The first and second hoist frames 12 and 22 comprise a pair of first installation brackets 13 and a pair of second installation brackets 23, and a first support bracket 14 and a second support bracket 24 installed between the first and second installation brackets 13 and 23 for supporting the same. In the inner sides of the first and second installation brackets 13 and 23, a first wire drum 15 and a second wire drum 25 wound with a first wire rope 16 and a second wire rope 26 are installed, respectively.
A first upper sheave 17 and a second upper sheave 27 are fixed at the lower sides of the first and second support brackets 14 and 24, and the first wire rope 16 and the second wire rope 26 wound on the first and second wire drums 15 and 25 are connected with the first and second hook units 18 and 28 through the first and second upper sheaves 17 and 27.
The first and second hook units 18 and 28 comprise a first lower sheave 20 and a second lower sheave 30 connected with the first and second wire ropes 16 and 26, respectively, and a first hook 19 and a second hook 29 installed in the first and second lower sheaves 20 and 30, respectively. A wire 35 is connected with the first hook 19 and the second hook 29 for turning the weight thing 36.
The connection member 31 comprises first auxiliary wheels 32 and second auxiliary wheels 33 installed in the first and second installation brackets 13 and 23, respectively, and a connection bracket 34 for connecting the first and second auxiliary wheels 32 and 33.
In the turning device for a conventional hoist, since the friction pulley 5 of FIG. 1 is not used, a slippery does not occur between parts even when it is used for a long time, and a driving transfer work is reliable between the parts. In addition, the weight thing 36 is supported by means of the first hook 19 of the first hoist unit 11 and the second hook 29 of the second hoist unit 21, respectively, so that the entire weight is divided into two hoist units 11 and 21 for thereby decreasing the over load in the turning device.
As shown in FIG. 4, in the turning device for a conventional hoist, when a certain weight thing 36 having a narrow width is turned, a worse problem may occur. Namely, in the turning device for a conventional hoist, since a space between the first and second hook units 18 and 28 is relatively wide, when a narrow weight thing is hoisted by hanging it to the wire 35, the wire 35 is not closely contacted with both sides of the weight thing 36.
The first and second hook units 18 and 28 are generally installed with a relatively wider space for the following reasons.
The connection member 31 is provided between the first and second installation brackets 13 and 23 for connecting the first and second hoist units 11 and 21. Since the space between the first and second hoist units 11 and 21 is widened owing to the connection member 31, the space between the first and second upper sheaves 17 and 27 is widened as well.
The first and second support brackets 14 and 24 with the first and second upper sheaves 17 and 27 are installed at the outer sides of the first and second wire drums 15 and 25, respectively. So, the space between the first and second upper sheaves 17 and 27 installed in the first and second support brackets 14 and 24 is widened as well.
In the turning device for a conventional hoist, the space between the first and second upper sheaves 17 and 27 is relatively wider. So, when a weight thing 36 with a narrow width is hoisted, the wire 35 is not closely contacted with both sides of the weight thing 36 as shown in FIG. 4.
When the wire 35 is not closely contacted with both sides of the weight thing 36 in a state the wire 35 is largely spaced apart from the both sides of the weight thing 36, it is impossible to keep the weight thing 36 balanced, and the weight thing 36 may largely swing by means of a certain external force.
In the above state, when a turning work is performed, the weight thing 36 may be tiled in one direction, and the weight center is moved. So, the part of the turning device 10 including the wire 35 may be severely damaged. When the parts are damaged, the weight thing 36 may fall down for thereby causing a safety accident.